Balance Shaft: Service and Repair

Oil Pump with Balance Shaft Drive

=> [ Chain Tensioner, Pre-tensioning ]

Special tools, testers and auxiliary items required

• Connecting Pin (T10027)

• Silicone Sealant (D 176 404 A2)

Removing

- Remove the oil pan. Refer to => [ Oil Pan ] Oil Pan.

- Remove the chain guard. Disengage the locking lugs through the openings - arrows - if necessary using a small screwdriver.





- Loosen the bolt for the oil pump chain sprocket. Counter hold at the vibration damper center bolt.





CAUTION!
The chain sprocket driving the balance shafts must not be loosened!

- Release tension on the chain tensioner using a screwdriver - arrow - and secure it using a 3 mm hex wrench - 1 -, across the flats.





- Remove the oil pump chain sprocket and disengage the chain from the balance shaft drive.





- Loosen the bolts for the balance shaft drive working from the outside toward the inside and remove it. Oil pump with balance shaft drive overview. Refer to => [ Oil Pump with Balance Shaft Drive Overview ] Lubrication System Overview.





Installing and Adjusting

• Chain tensioner pre-loaded, refer to => [ Chain Tensioner, Pre-tensioning ].

- Place the intermediate plate as shown onto the alignment bushings - arrows - in the balance shaft drive.





- Install the oil pump with balance shaft drive and intermediate plate. Tighten the bolts from the inside working toward the outside to 15 Nm + an additional 90° (1/4) turn.





• Note the different length of bolts.

- Turn the crankshaft to set cylinder 1 at Top Dead Center (TDC).





- Set the mark on the balance shaft chain sprocket - arrow - opposite the alignment bore. Secure the chain sprocket in this position using (T10027). Place the chain onto the balance shaft chain sprocket.





- Install the oil pump chain sprocket and tighten the bolt by hand.

• The oil pump chain sprocket fits only in one position. To install, only the oil pump must be turned.

- Remove the (T10027) and the hex wrench - 1 -. Tighten the oil pump chain sprocket bolt. Tightening specification: 20 Nm + an additional 90° (1/4) turn. Counter hold at the vibration damper center bolt.





- Install the oil pan. Refer to => [ Oil Pan ] Oil Pan.

The rest of the installation is basically a reverse of the removal sequence.

Balance Shaft Drive Bolt Allocation





A M7 x 40 bolt
B M7 x 70 bolt
C M7 x 90 bolt
D M7 x 55 bolt
E Sealing plug with O-ring

Chain Tensioner, Pre-tensioning

- Pretension the piston - arrow - by hand.





- Push the chain rail in the - direction of the arrow - and secure it with a 3 mm hex wrench - 1 -.